The invention concerns a soil replacement method and system suitable for growing plants. Instead of soil, the invention utilizes a multi-layered gravel hydroponic structure that includes sedimentary-type organic pea gravel to provide both support and nutrients for plant growth in an indoor or outdoor environment.
Soil provides a traditional growing environment for vegetation and generally requires annual placements of nutrients and fertilizers to sustain growth. Water, air (i.e., oxygen) and temperature are required for seed germination. Nutrients are not generally needed at this stage since seed pods contain an initial supply of nutrients. After the roots sprout by breaking through the seed coat, plant growth ensues via photosynthesis by consuming water, air (e.g., nitrogen and oxygen), and nutrients. With soil, weeds are a constant problem and often require herbicides for their control or suppression. Soil degradation, especially with consumable crops, also reduces yield over time, pollute watersheds, and contribute to land erosion. In addition, poor soil conditions require increased watering and thus increased costs. Water escapes faster in soil, especially during droughts, which cause the surface of the ground to crack letting even more precious water evaporate into the atmosphere.
Hydroponic systems that grow plants in nutrient solutions eliminate soil but require constant pumping of water and nutrients to support plant growth. Such systems also require nutrient feeding equipment, frequent cleaning of waste buildup, and continuous maintenance to pump nutrient-enriched water to the roots. Prior hydroponic and/or plant cultivation systems are described in U.S. Pat. No. 8,001,721; 7,485,171; 5,557,885; 4,584,791; 4,630,394; 4,329,812; 4,399,634; and 4,148,155. Unlike the present invention, prior hydroponic systems utilizing gravel are not known to employ sedimentary-type organic rock, but instead, utilized metamorphic and igneous type rocks that were devoid of nutrients. A gravel hydroponic system in accordance with the present invention, on the other hand, is completely natural, does not require nutrient solutions and needs little care and maintenance.
Several attempts have been made in the past to facilitate seed germination and plant growth. U.S. Pat. No. 4,067,712 to Willard, for example, discloses the use of a catalyst mixed with soil to enhance seed germination. U.S. Pat. No. 4,171,968 to Farone discloses treating seeds with a surfactant in order to improve their germination. U.S. Pat. No. 4,140,421 shows an underground piping system to provide watering of a growing region.